Archive for December 20th, 2012

A spectacular glaciated valley near Ardara, County Donegal, Ireland

December 20th, 2012

GlacialValleyArdaraDONEGAL, IRELAND — One last post from a great day in the Irish countryside. The above is Glengesh Pass, with the town of Ardara in the background. Glengesh means “Glen of the Swans”. On the south side (right in this image) is Common Mountain (503 meters high). This is a classic U-shaped glaciated valley. Someone has actually posted a YouTube video of driving through Glengesh Pass. (The accompanying music is an eccentric modern Irish ballad called “Las Vegas in The Hills of Donegal“. The fourth ranked Irish single in 1992!)

Slieve League, County Donegal, Ireland

December 20th, 2012

SlieveLeagueOneDONEGAL, IRELAND — The above peak sweeping precipitously down into a raging sea is the smaller of the exposures at Slieve League along the southern coast of County Donegal. These are the highest sea cliffs in Ireland, and among the highest in Europe. The road getting to this point had spectacular views along the way. (“Spectacular” means, of course, terrifying.)

SlieveLeagueThreeThis is a view of the highest of the Slieve League peaks, hidden by the fog. It is just over 600 meters from the sea to the peak. The trail up to it is said to be bracing.

SlieveLeagueTwoThe maelstrom at the base of Slieve League. This coast of Ireland has some of the best surfing in Europe, facing as it does the North Atlantic. Surfing right here, though, would be a bit tricky, but there is a landing beach.

Screen shot 2012-12-20 at 3.21.27 PMShanbally on the middle right in this Google Map is the highest point of Slieve League.

FoldedRocks122012There is some structural geology going on as you can see from these folded quartzites just east of Slieve League on Carrigan Head.

The Grianán of Aileach

December 20th, 2012

GriananOutsideDONEGAL, IRELAND — In the northeastern part of the county, about 7 km west of Derry in Northern Ireland, is Greenan Mountain. On its very top is a spectacular ringfort called The Grianán of Aileach (“the Solarium of Aileach”, shown above). From it are spectacular views of the countryside 360° around. It is a majestic and yet rather lonely place, maybe because my new friend Andy Quinn and I were the only ones there. It was probably built in some form around the beginning of the common era and no doubt occupied by many successive groups. There is a burial mound on the site (a tumulus) that may date back to 3000 BCE. The local story is that it was originally a place to honor the sun (which I would not have minded seeing today).

The fort’s most prominent days were when it was the royal citadel of the northern Ui Neill sept of Aileach from the 5th to the 12th century. The stone portion of the fort was destroyed in 1101 by Murtogh O’Brien, King of Munster. His soldiers were ordered to take the fort apart and scatter its stones widely. In 1870 it was substantially restored to its present state.

The Grianán of Aileach was an excellent location to visit and have a look at the countryside of eastern County Donegal. The rocks exposed here are among the oldest in Ireland (Late Proterozoic to Early Cambrian).

GriananInsideThe inside of the circular Grianán of Aileach. There are three interior platforms connected by narrow stairs. There is some dispute over whether this was the original architecture of the ringfort before its destruction in 1101.

GriananRocksThe stones are mostly without mortar. They appear to be some kind of quartz mica schist.

GriananPanorama585I tried a panorama of Lough Swilly to the west of the ringfort. It doesn’t convey the real sweeping vista in 585 pixels wide, but you get the idea of a cool view!

GriananHolyWellThis is a “holy well” to the southeast of the ringfort. It is said to have been visited by St. Patrick himself. Then again, everyone wants a connection to The Man!

An Irish myth says that The Grianán of Aileach was built by King Daghda of Tuatha de Danann, and that the grave of his son lies beneath the fortress forever guarding it. In any case, we were suitably respectful of this ancient site.